HiRise, the high resolution camera on board NASA’s Mars Reconnaissance Orbiter (MRO), is a $40 million piece of equipment that was built under the direction of the University of Arizona’s Lunar and Planetary Laboratory.

HiRise has been taking groundbreaking pictures of Mars’ surface since 2006 and remains the largest of its kind to embark on a deep space mission. However, it has yet to capture any signs of life lurking in the dark shadows of these martian pits.

The first pit was discovered on Mars in 2007, but the collection of dust and other materials conceal what (or who) could be hiding underneath. It’s generally thought that the pits are simply sinkholes that have formed over collapsed lava tubes leading to nearby volcanoes.

NASA reported that the dark pit, spotted along the southeastern flank of Arsia Mons, was “really a vertical shaft that cuts through lava flow”, but that the angle of images captured makes it look more like a crater than a channel.